JEFFERSON CITY, Mo. (AP) — Missouri’s Republican Senate leader is proposing a sweeping overhaul of a state consumer-protection law that’s being used in a class-action lawsuit against the company of one of his largest donors.

Senate President Pro Tem Ron Richard told reporters Thursday that close to $300,000 in campaign donations he’s received since 2011 from the wealthy Humphreys family didn’t influence him.

David Humphreys is president and CEO of Joplin-based TAMKO Building Products Inc. A Missouri church filed a class-action lawsuit in 2014 against the company under the law Richard is trying to overhaul, alleging TAMKO sold shoddy shingles.

At issue is the state’s Merchandising Practices Act, which was enacted in 1967 in an attempt to help consumers join together to fight back against business fraud or deception.

There’s disagreement between opposing trial attorneys and supportive business groups over what Richard’s proposal would do if enacted. But it generally would limit plaintiffs’ ability to sue individually or in class-action lawsuits under the consumer-protection law.

Missouri Association of Trial Attorneys Deputy Director Sharon Jones said as is, the bill would effectively eliminate state class-action lawsuits under that law.

Richard told reporters restricting class-action lawsuits “sounds like a great idea.”

Richard and others, such as the Missouri Chamber of Commerce and the Washington, D.C.-based American Tort Reform Association, say there are too many lawsuits filed in Missouri against businesses under the act.

“Consumer protection law over the last 40 some odd years has been eroded to the point where it’s become a haven for plaintiffs’ attorneys,” Missouri Chamber of Commerce and Industry lobbyist Brian Bunten said.

A list of lawsuits provided to The Associated Press from both the Missouri Chamber and ATRA includes recent cases over ingredients in cupcake mixes and whether those products and others can be labeled “natural.” Many of those lawsuits were dismissed.

Richard’s bill is up for debate on the Senate floor, but he and Senate Majority Leader Mike Kehoe told reporters he’s still working on tweaking it.

Among other things, Richard’s bill would:

— Change current law that allows lawsuits to be filed under the Merchandising Practices Act up to five years after a problem with the product or other transaction is discovered. Under the bill, the five-year deadline would start when a product is purchased.

Under that policy, the Missouri church likely would not have been able to sue TAMKO. The Jonesburg United Methodist Church bought TAMKO shingles in 2007. According to court records, the church found leaks in its ceiling “related to its shingles’ failures” five years later in 2013. It filed suit the next year, in 2014.

— Require all individuals in class-action lawsuits to prove they were harmed and submit statements laying out exactly how much money a fraudulent or deceptive sale cost them. Jones said in practice that would kill class-action lawsuits under the Merchandising Practices Act. Those can have hundreds or thousands of participants.

Bunten said that’s “not at all what we’re trying to do.”

“We don’t feel like filling out a one-page form is too much to ask of someone if they’re making a claim,” he said.

The bill also would prevent smaller groups of similarly harmed plaintiffs from joining together to sue.

— Block individuals from suing under the consumer-protection law for anything “otherwise permitted, approved, or regulated” by state or federal agencies.

“Almost every industry in the state is regulated by somebody,” Jones said.

But Bunten said that’s “simply not the case.” He said the aim is for claims of misconduct to be handled by the agencies that regulate those industries.